In a heartwarming video, posted by Zac's parents, they expressed their sincere gratitude to everyone who has helped their son.
"12 months ago today our little warrior was knocked down in a hit and run outside our home.
"We have made a short video to say thank you and show his progress to date.
"Many long nights in dark places but this fella's smile makes it all worthwhile," Zac's father Paul wrote on social media.
"To my wife who has been incredible with Zac thank you.
"Thanks to Evolve Therapy Mallow, Aine and Emily, who have been incredible with Zac who is a different boy to whom they began working with in May 2019," he continued.
Paul thanked the hospitals who went "above and beyond" to help their son and to the community in Mahon for their continued support.
"Final huge thanks to doctors, and more importantly, the nurses of St Gabriel's Ward in Temple Street, Dublin. True everyday superheroes," Paul added.
On this day last year, Zac was struck by a vehicle at Castle Meadows on the Skehard Road outside his home.
He suffered from a serious brain injury and had to re-learn how to walk and talk.
However, as the video shows, the toddler has been recovering well with the combined support of medical teams, his family and the people of Cork.